Partial and Full Arc Volumetric Modulated Arc Therapy in Lung Cancer Stereotactic Body Radiotherapy with Different Definitions of Internal Target Volume Based on 4D CT

Purpose: To investigate the feasibility of partial arc volumetric modulated arc therapy (VMAT) in lung cancer stereotactic body radiotherapy (SBRT), as well the volumetric and dosimetric effects of different internal target volume (ITV) definitions with 4D CT. Methods: Fourteen patients with primary and metastatic lung cancer underwent SBRT were enrolled. Full and partial arc VMAT plans were generated with four different ITVs: ITVall, ITVMIP, ITVAIP and ITV2phases, representing ITVs generated from all 10 respiratory phases, maximum intensity projection (MIP), average intensity projection (AIP), and 2 extreme respiratory phases. Volumetric and dosimetric differences, as well as MU and delivery time were investigated. Results: Partial arc VMAT irradiated more dose at 2 cm away from planning target volume (PTV) (P = 0.002), however, it achieved better protection on mean lung dose , lung V5, spinal cord, heart and esophagus compared with full arc VMAT. The average MU and delivery time of partial arc VMAT were 240 and 1.6 min less than those of full arc VMAT. There were no significant differences on target coverage and organ at risks (OARs) sparing among four ITVs. The average percent volume differences of ITVMIP, ITVAIP and ITV2phases to ITVall were 8.6%, 13.4%, and 25.2%, respectively. Conclusions: Although partial arc VMAT delivered more dose 2 cm out of PTV, it decreases the dose to lung, spinal cord, and esophagus, as well decreased the total MU and delivery time compared with full arc VMAT without sacrificing target coverage. Partial arc VMAT was feasible and more efficient for lung SBRT.

Dosimetric Impact of Tumor Position and Lung Density Variations in Lung Stereotactic Body Radiotherapy

Purpose of this study was to evaluate the variation of the dose to gross tumor volume (GTV) related to tumor position and lung density for lung stereotactic body radiotherapy (SBRT) using a virtual phantom. The density of the equivalent lung surrounding the GTV (10 mm diameter) was defined as 0.10, 0.15, 0.25, 0.35, and 0.45 g/cm3. A planning target volume (PTV) was generated by adding a uniform 8 mm margin to the internal target volume (ITV). We defined that the 99% of the GTV should be covered by 100% of the prescribed dose using Monte Carlo (MC) calculation. The GTV structure was replicated from ITV to the PTV periphery at 1 mm intervals. Planned dose to the GTV was defined as the predicted dose in the replicated GTV structure. Simulated dose to the GTV was defined as the calculated dose in the replicated GTV structure taking into account the tumor position error. D99 of the planned dose to the GTV at the 8 mm shift position was 78.1%, 81.6%, 87.3%, 91.4% and 94.4% at equivalent lung densities of 0.10, 0.15, 0.25, 0.35, and 0.45 g/cm3, respectively. D99 of the simulated dose to the GTV at the 8 mm shift position was 96.9%, 95.3%, 94.2%, 95.1 % and 96.3% at equivalent lung densities of 0.10, 0.15, 0.25, 0.35, and 0.45 g/cm3, respectively. Planned dose to GTV is strongly dependent on lung density and tumor position errors, while simulated dose to GTV does not show any significant dependence.

Comparison of Stereotactic Body Radiotherapy Delivery Techniques for Early-Stage Lung Cancer Using Lung Toxicity Modeling

Purpose: Lung toxicity is a primary side effect in stereotactic radiotherapy (SBRT) for early-stage non-small cell lung cancer (NSCLC). We aimed to use a set of radiobiological models to evaluate and compare modern IMRT delivery techniques with three-dimensional conformal techniques for SBRT treatment of NSCLC in terms of lung toxicity, and aimed to compare the results from different radiobiologcal models. Methods: Ten early-stage NSCLC patients treated with SBRT were retrospectively selected. Five treatment plans were generated to deliver 50 Gy in five fractions to the planning target volume for each case: a helical tomotherapy (HT) plan, two three-dimensional cofnromal radiotherapy (3D-CRT) plans using 6-MV and 10-MV photon beams respectively, and two volumetric modulated arc therapy (VMAT) plans using one and two arc fields respectively. The lung RDV was calculated with three parallel functional sub-unit (FSU) models and two normal tissue complication probability (NTCP) models. Results: Both the HT and VMAT plans showed significantly higher contralateral mean lung dose and lower ipsilateral mean lung dose compared to the 3D-CRT plans. There was no statistically significant difference in terms of lung toxicities between the IMRT and 3D-CRT techniques using either the FSU models or the NTCP models. Based on both the FSU and the NTCP models, there was strong correlation between lung toxicity and the mean lung dose in SBRT treatment plans. Conclusions: Based on both the NTCP and parallel FSU models, both IMRT and traditional 3D-CRT delivery techniques could achieve comparable lung sparing inn SBRT treatment of early-stage lung cancer. However, the validity of the radiobiological model results should be checked by clinical data.

Lung Stereotactic Body Radiotherapy Using an Abdominal Compression System, “Air-Bag System”

We investigated respiratory tumor motion in lung stereotactic body radiotherapy (SBRT) with use of the “Air-Bag System”. 114 patients underwent four-dimensional (4D) computed tomography (CT) from October 2010 to April 2012. Gross tumor volume (GTV) was 8.1 ± 11.0 cc (range 0.3 - 77.5 cc). The tumor site was the upper and middle lobes in 62 cases, and lower lobe in 52 cases. The Air-Bag SystemTM consists of an inelastic air bag connected to a second smaller elastic air bag. The inelastic air bag is placed between the patient’s body surface and a HipFix and is secured by pressure adjustment via the elastic air bag. To assess respiratory tumor motion, the centroid of the tumor position is measured in the left-right, anterior-posterior, and caudal-cranial directions using the iPlan RT DoseTM treatment planning system. Respiratory tumor motion vector for patients with upper/middle and lower lobe tumors was 3.0 ± 2.2 mm (range, 0.4 - 11.7 mm) and 6.5 ± 4.6 mm (range, 0.4 - 22.0 mm) respectively, with this difference being significant (p < 0.05). Mean respiratory tumor motion for all patients was 0.9 ± 0.6 mm (range, 0.1 - 3.6 mm) in the left-right direction, 1.5 ± 1.1 mm (range, 0.1 - 5.7 mm) in the anterior-posterior direction, 4.1 ± 4.0 mm (range, 0.1 - 21.4 mm) in the caudal-cranial direction, and 4.7 ± 4.0 mm (range, 0.4 - 22.0 mm) overall. The Air-Bag System is expected to be provided an effective reduction in the motion of lung tumors.

A phase I radiation dose escalation of stereotactic body radiotherapy for malignant lung tumors

Objectives: This Phase I study determines the maximum tolerated dose (MTD) of stereotactic body radiotherapy (SBRT) for lung tumors. Methods: Eli- gible patients had biopsy proven cancer with a maxi- mum tumor size ≤ 5 cm. Total doses were escalated from 40 to 48, then to 56 Gy, delivered in 4 equal fractions administered 2 to 3 times per week on an IRB approved protocol. SBRT was administered us- ing 5 to 9 fixed beam arrangements with CT loca- lization. Internal target volumes (ITV) were based on breath hold scans or 4D CT simulation. The planning target volume (PTV) was defined as the ITV with a uniform 5 mm expansion. Dose limiting toxicity (DLT) was defined as any grade 3 or higher toxicity using the Radiation Therapy Oncology Group (RTOG) common toxicity criteria (CTC). Results: Between April 2004 and February 2008, 18 patients received the prescribed treatment (40 Gy n = 6, 48 Gy n = 7, 56 Gy n = 5). Seventeen of 18 patients had non-small cell lung cancer (1 with rectal cancer), four of whom were treated for an oligometastasis. The median age of the patients was 68, while the median Karnofsky performance status was 90. The mean tumor size was 2.6 cm (range 0.9 to 4.5 cm). One grade 3 pulmonary event occurred (at 48 Gy dose level) immediately following treatment with the onset of fever and shortness of breath that responded to antibiotics. No other DLTs occurred. Conclusions: SBRT utilizing patient specific target volumes without gating appears safe. The maximum tolerated dose was not reached.

Delivered Dose Verification for Lung Cancer Stereotactic Body Radiotherapy Using Cone-Beam CT

Purpose: Verified the delivered dose distribution of lung cancer Stereotactic Body Radiotherapy (SBRT) using the cone-beam CT images. Methods: Twenty lung cancer patients who underwent SBRT with 100 CBCT images were enrolled in this study. Delivered dose distributions were recalculated on CBCT images with the deformed and non-deformed methods, respectively. The planned and delivered dose distributions were compared using the dose-volume histograms. Results: The delivered target coverage (V100) per patient inside target volume deviated on average were 0.83% ± 0.86% and 1.38% ± 1.40% for Pct vs. Pcbct and Pct vs. Pdcbct, respectively. The Conformity Index (CI) and Gradient Index (GI) showed a good agreement among the plans. For the critical organs, only minor differences were observed between the planned dose and the delivered dose. Conclusions: CBCT images were a useful tool for setup and dose delivery verification for lung cancer patients who underwent SBRT.

Stereotactic body radiation therapy for non-small cell lung cancer:A review

Stereotactic body radiation therapy(SBRT) is the treatment of choice for medically inoperable patients with early stage non-small cell lung cancer(NSCLC). A literature search primarily based on PubMed electronic databases was completed in July 2018. Inclusion and exclusion criteria were determined prior to the search, and only prospective clinical trials were included. Nineteen trials from 2005 to 2018 met the inclusion criteria, reporting the outcomes of 1434 patients with central and peripheral early stage NSCLC. Patient eligibility,prescription dose and delivery, and follow up duration varied widely. Threeyears overall survival ranged from 43% to 95% with loco-regional control of up to 98% at 3 years. Up to 33% of patients failed distantly after SBRT at 3 years. SBRT was generally well tolerated with 10%-30% grade 3-4 toxicities and a few treatment-related deaths. No differences in outcomes were observed between conventionally fractionated radiation therapy and SBRT, central and peripheral lung tumors, or inoperable and operable patients. SBRT remains a reasonable treatment option for medically inoperable and select operable patients with early stage NSCLC. SBRT has shown excellent local and regional control with toxicity rates equivalent to surgery. Decreasing fractionation schedules have been consistently shown to be both safe and effective. Distant failure is common, and chemotherapy may be considered for select patients. However, the survival benefit of additional interventions, such as chemotherapy, for early stage NSCLC treated with SBRT remains unclear.

Survey of Stereotactic Body Radiation Oncology for Early Staged Non-Small Cell Lung Cancer in China

Purpose: To evaluate the current status of stereotactic body radiotherapy (SBRT) for early staged non-small cell lung cancer (NSCLC) at main cancer hospitals in China. Methods and Materials: The questionnaire was sent by mail and email to 21 hospitals, which include the patient enrollment, treatment technique, dose and fractionation, quality control, disease control and side effects. Results: Nineteen hospitals responded. It was found that SBRT has been used for early staged NSCLC in most of the hospitals participating in the survey. The patient characteristics and techniques were relatively consistent, but there were many controversies regarding dose fractionation and quality control. Conclusions: SBRT for early staged NSCLC has been applied at main cancer hospitals in China. However, considerable variation exists. The establishment of clinical guidelines and standardized quality control are crucial for further improvement.

Single-fraction stereotactic ablative body radiation therapy for primary and metastasic lung tumor:A new paradigm?

Stereotactic ablative body radiotherapy(SABR)is an effective technique comparable to surgery in terms of local control and efficacy in early stages of non-small cell lung cancer(NSCLC)and pulmonary metastasis.Several fractionation schemes have proven to be safe and effective,including the single fraction(SF)scheme.SF is an option costeffectiveness,more convenience and comfortable for the patient and flexible in terms of its management combined with systemic treatments.The outbreak of the severe acute respiratory syndrome coronavirus 2 pandemic has driven this not new but underutilized paradigm,recommending this option to minimize patients’visits to hospital.SF SABR already has a long experience,strong evidence and sufficient maturity to reliably evaluate outcomes in peripheral primary NSCLC and there are promising outcomes in pulmonary metastases,making it a valid treatment option;although its use in central locations,synchronous and recurrencies tumors requires more prospective safety and efficacy studies.The SABR radiobiology study,together with the combination with systemic therapies,(targeted therapies and immunotherapy)is a direction of research in both advanced disease and early stages whose future includes SF.

Percutaneous local tumor ablation vs. stereotactic body radiotherapy for early-stage non-small cell lung cancer: a systematic review and meta-analysis

Background:Percutaneous local tumor ablation(LTA)and stereotactic body radiotherapy(SBRT)have been regarded as viable treatments for early-stage lung cancer patients.The purpose of this study was to compare the efficacy and safety of LTA with SBRT for early-stage non-small cell lung cancer(NSCLC).Methods:PubMed,Embase,Cochrane library,Ovid,Google scholar,CNKI,and CBMdisc were searched to identify potential eligible studies comparing the efficacy and safety of LTA with SBRT for early-stage NSCLC published between January 1,1991,and May 31,2021.Hazard ratios(HRs)or odds ratios(ORs)with 95%confidence intervals(CIs)were applied to estimate the effect size for overall survival(OS),progression-free survival(PFS),locoregional progression(LP),and adverse events.Results:Five studies with 22,231 patients were enrolled,including 1443 patients in the LTA group and 20,788 patients in the SBRT group.The results showed that SBRT was not superior to LTA for OS(HR=1.03,95%CI:0.87-1.22,P=0.71).Similar results were observed for PFS(HR=1.09,95%CI:0.71-1.67,P=0.71)and LP(HR=0.66,95%CI:0.25-1.77,P=0.70).Subgroup analysis showed that the pooled HR for OS favored SBRT in patients with tumors sized>2 cm(HR=1.32,95%CI:1.14-1.53,P=0.0003),whereas there was no significant difference in patients with tumors sized≤2 cm(HR=0.93,95%CI:0.64-1.35,P=0.70).Moreover,no significant differences were observed for the incidence of severe adverse events(≥grade 3)(OR=1.95,95%CI:0.63-6.07,P=0.25)between the LTA group and SBRT group.Conclusions:Compared with SBRT,LTA appears to have similar OS,PFS,and LP.However,for tumors>2 cm,SBRT is superior to LTA in OS.Prospective randomized controlled trials are required to determine such findings.

中晚期非手术治疗肺癌患者应用卡瑞利珠单抗联合立体定向体部放疗的有效性研究

目的评估卡瑞利珠单抗联合立体定向体部放疗(SBRT)在中晚期非手术治疗肺癌中对生存期及治疗安全性的影响价值。方法采用回顾性分析,选择2020年4月—2022年10月赤峰市医院放疗科收治的中晚期非手术治疗肺癌患者300例,根据临床治疗方式不同,分为对照组(150例,SBRT治疗)与研究组(150例,SBRT治疗基础上静脉注射卡瑞利珠单抗,3周/次,共计4次)。两组均治疗3个疗程(21 d为1个疗程)。收集两组临床信息对比治疗效果、治疗前后炎症因子(IL-6、IL-10)、肿瘤坏死因子(TNF-a)、血管内皮因子(bFGF、Ang-2、VEGF、MMP-9)变化情况、机体免疫状况(CD4+、CD8+、NK)及治疗期间不良反应。结果研究组治疗有效率高于对照组,IL-6、IL-10水平低于对照组,TNF-a水平高于对照组(P<0.05);研究组bFGF、Ang-2、VEGF、MMP-9均低于对照组(P<0.05);研究组干预后机体免疫T细胞亚群CD4+、CD8+、NK高于对照组(P<0.05);两组治疗不良反应比较,差异无统计学意义(P>0.05)。结论卡瑞利珠单抗联合立体定向体部放疗(SBRT)在中晚期非手术治疗肺癌中展现了较好的生存期延长和治疗安全性,可通过调节炎症因子、肿瘤坏死因子和血管内皮因子的水平,以及增强机体的免疫功能,达到更好的治疗效果和较低的不良反应,临床应用价值高。

放疗联合帕博利珠单抗治疗晚期非小细胞肺癌的临床效果

目的 探究立体定向体放射治疗(SBRT)联合帕博利珠单抗对晚期非小细胞肺癌(NSCLC)患者生存和肿瘤反应影响。方法 对2019—2020年期间在攀枝花市中西医结合医院接受一线帕博利珠单抗化疗的NSCLC患者病历进行回顾性分析,共纳入符合标准的患者116例,共有32.8%(38/116)的患者接受了SBRT,纳入联合组,其余患者纳入单用组。使用Kaplan-Meier模型评估2组中位无进展生存期(PFS)和总生存期(OS)。记录比较2组的不良反应发生情况。结果 整个队列的中位PFS为12.00个月(95%CI:10.17~13.83),和中位OS为23.43个月(95%CI:20.04~26.82)。多变量分析显示,SBRT治疗是PFS(HR:0.45,95%CI:0.65~0.93,P=0.020)和OS(HR:0.32,95%CI:0.53~0.87,P=0.013)的独立预测因素。联合组的中位PFS为13.97个月(95%CI:12.04~15.89),而单用组为10.08个月(95%CI:7.90~12.27)(P=0.016)。联合组的中位OS为30.67个月(95%CI:22.20~39.14),而单用组为21.97个月(95%CI:18.64~25.30)(P=0.011)。2组间总体不良事件发生率比较差异无统计学意义(P>0.05),联合组3级或3级以上肺炎的发生率略高于单用组(7.89%vs 3.87%),但差异无统计学意义(P=0.350)。结论 在一线帕博利珠单抗治疗期间,联合SBRT可改善晚期NSCLC患者的PFS和OS,且不增加治疗毒性。

基于4D-CT的三种呼吸门控技术对肺癌立体定向放射治疗计划靶区及正常组织器官体积、受照剂量的影响

目的:探讨基于4D-CT的三种呼吸门控技术对肺癌立体定向放射治疗(SBRT)计划靶区及正常组织器官体积、受照剂量的影响。方法:收集108例肺癌患者的病例资料,比较患者在基于4D-CT的三种呼吸门控技术下接受SBRT治疗的肿瘤靶区(GTV)、计划靶区(PTV)体积和受照剂量,并比较三种呼吸门控技术下正常组织的受照剂量。结果:三种不同技术下,患者GTV与PTV体积比较存在统计学意义差异(均P<0.05),其中自由呼吸(FB)技术下的GTV与PTV体积较主动呼吸控制(ABC)、呼吸门控(RG)技术下高,RG技术下GTV与PTV体积较ABC技术下高(均P<0.05);三种不同技术下PTV受照剂量参数靶区适形度指数(CI)水平差异无统计学意义(均P>0.05);三种不同技术下PTV受照剂量参数靶区剂量均匀性指数(HI)、GI水平差异有统计学意义(均P<0.05);其中FB技术下的GI较ABC技术和RG技术下低,HI水平较ABC技术和RG技术下高,ABC技术下的HI水平较RG技术下低(均P<0.05);三种不同技术下心脏、大血管、气管、食管以及脊髓的受照剂量比较差异无统计学意义(均P>0.05);三种不同技术下双肺V_(5)、V_(20)以及平均照射剂量(MLD)比较差异有统计学意义(均P<0.05);FB技术下的V_(5)、V_(20)以及MLD较ABC、RG技术下高,RG技术下V_(5)、V_(20)以及MLD较ABC技术下高(均P<0.05)。结论:基于4D-CT的ABC与RG技术相较于FB技术更有利于缩小靶区体积,提高治疗剂量,同时更有利于降低病灶危及器官与组织的受照剂量。

射波刀治疗老年早期非小细胞肺癌的治疗效果与安全性

目的探讨射波刀治疗老年(≥75岁)早期非小细胞肺癌(non-small cell lung cancer,NSCLC)患者的有效性与安全性,并与<75岁患者的结果对比。方法回顾性分析2013年1月至2019年10月济南市解放军第960医院收治的75例早期(T1-2N0M0)NSCLC患者。<75岁患者32例(42.7%),≥75岁患者43例(57.3%)。所有患者剂量方案为45~66Gy/3~8F,60%~85%等剂量线作为处方剂量包绕计划靶区(planning target volume,PTV),每日1次,每周5次。比较两组患者临床治疗效果、生存状况及治疗毒性,并分析影响≥75岁患者生存期的因素。结果<75岁和≥75岁患者疾病控制率分别为96.9%和93.0%(P>0.05)。5年局部控制率(local control,LC)、无进展生存率(progression-free survival,PFS)和癌症特异性生存率(cancer-specific survival,CSS)分别为70.9%和85.4%,58.5%和54.4%,70.4%和64.5%,差异均无统计学意义(P>0.05)。但≥75岁患者的生存率(overall survival,OS)明显低于<75岁患者,5年OS分别为49.2%和68.2%(P<0.05)。两组患者的治疗并发症比较,差异无统计学意义(P>0.05)。多因素分析发现生物等效剂量(biologic effective dose,BED)是影响老年患者OS的独立因素。结论采用射波刀对不适合手术的老年早期NSCLC患者行立体定向放射治疗是一种安全有效的治疗方式。

非小细胞肺癌同层双转移病灶SBRT-VMAT计划设计方式研究

目的:研究非小细胞肺癌同层双转移病灶立体定向放射治疗(stereotactic body radiation therapy,SBRT)时不同计划方式对肺的受量、机器跳数、适形性指数(conformity index,CI)及剂量梯度(gradient index,GI)的影响,以为此类患者治疗计划的设计提供参考。方法:选取非小细胞肺癌单侧同层双转移病灶患者共11例,采用容积旋转调强放疗(volumetric modulated arc therapy,VMAT)技术制订3种SBRT计划。根据4D-CT定位方式的最大投影图像勾画内靶区ITV1、ITV2,均匀外放3 mm得到计划靶区PTV1、PTV2,并将PTV1与PTV2相加得到PTV12。第1种计划方式以PTV1和PTV2靶区中心为治疗中心,制订2个单独计划plan-1与plan-2,合并为plan-sum后进行剂量评估;第2种计划方式分别以PTV1和PTV2中心为治疗中心,制订多中心的计划plan-D。第3种计划方式以PTV12的中心为治疗中心,制订单中心计划plan-S。将plan-sum的plan-1与plan-2分别归一到PTV1和PTV2 95%体积以满足处方剂量,将plan-S与plan-D归一到PTV12 95%体积以满足处方剂量。比较3种计划方式下肺的受量、机器跳数、CI及GI。采用SPSS 25.0软件进行统计学分析。结果:plan-S除V_(5)与plan-sum相比差异无统计学意义(P>0.05)外,V_(10)、V_(20)、V_(30)及平均剂量均低于plan-sum,差异有统计学意义(P<0.05);plan-D肺的受量和平均剂量均低于plan-sum,差异有统计学意义(P<0.05);plan-S与plan-D计划方式下肺的受量差异无统计学意义(P>0.05)。plan-sum的CI低于plan-S和plan-D,差异有统计学意义(P<0.05);plan-S与plan-D的CI差异无统计学意义(P>0.05)。plan-D的GI低于plan-S和plan-sum,差异有统计学意义(P<0.05);plan-S与plan-sum的GI差异无统计学意义(P>0.05)。plan-D和plan-sum的机器跳数高于plan-S,差异有统计学意义(P<0.05);plan-D与plan-sum的机器跳数差异无统计学意义(P>0.05)。结论:若患者身体状况支持长时间保持定位姿势,可以采用多中心的计划方式优化剂量分布和提高适形度;若患者身体状况较差,可以采用单中心的计划方式缩短治疗时间。

4DCT联合呼吸管理对NSCLC SBRT治疗精度的影响

目的通过对比四维X线断层扫描(four dimension computed tomography,4DCT)联合呼吸门控、腹部加压以及自由呼吸模式下立体定向放射治疗(stereotactic body radiotherapy,SBRT)计划参数的对比,分析呼吸管理对肿瘤靶区体积、剂量精度的影响。方法选取2021年10月—2022年12月在山东第一医科大学附属中心医院肿瘤科就诊的12例早期非小细胞肺癌(non-small cell lung cancer,NSCLC)采用立体定向放射治疗的患者,分别设计3套图像计划,每套图像12例为一组。搜集4DCT扫描图像,按呼吸时相将CT数据重建,分层处理得到0%~90%图像(0%为吸气末,50%为呼气末),勾画各时相肿瘤靶区,利用最大密度投影融合成全时相图像,用来模拟自由呼吸模式下的普通CT图像(FB'组);将30%~70%时相图像用最大密度投影融合,因其与利用呼吸附件腹部加压后其呼吸时相相同,定义为腹部适度加压组图像(RA'组);将吸气末0%时相图像模拟主动呼吸控制状态图像(ABC'组)。在这3组图像上分别得到肿瘤靶区、肿瘤内靶区及计划靶区,比较3组治疗模式中肿瘤靶区及危机器官剂量学差异。结果(1)ABC'组、RA'组及FB'组肿瘤内靶区体积值差异有统计学意义(P<0.05)。计划靶区适形性指数、均匀性指数、5%计划靶区(planned target volume,PTV)体积的剂量及体积的剂量、及95%PTV体积的剂量差异均无统计学意义(P>0.05)。(2)ABC'组、RA'组及FB'组患者计划靶区双肺剂量5 Gy照射时的百分体积、双肺剂量20 Gy照射时的百分体积、平均肺剂量,差异有统计学意义(P<0.05)。心脏最大剂量、<15 cm^(3)体积的剂量示RA'组、ABC'组均略低于FB'组,但差异无统计学意义(P>0.05)。结论在非小细胞肺癌立体定向放射治疗中应用呼吸门控、适度腹部加压等呼吸管理方式联合4DCT,较自由呼吸模式下的FB'组有效地减小肿瘤内靶区体积、双肺剂量5 Gy的百分体积、双肺剂量20 Gy的百分体积、平均肺剂量等指标,减少呼吸动度对靶区的影响,提高定位、治疗的精度。腹部加压呼吸管理技术是对呼吸门控呼吸管理技术不适应者的一种有效补救措施。

锥形束CT对非小细胞肺癌患者体部立体定向放疗法中图像引导准确性、摆位误差的影响

目的探讨锥形束CT(CBCT)对非小细胞肺癌(NCSLC)患者体部立体定向放疗法(SBRT)中图像引导准确性、摆位误差的影响。方法选取我院收治的NCSLC患者97例,均行SBRT治疗。研究对象均行CBCT采集图像。于SBRT治疗前行CBCT扫描,扫描获取图像和计划CT图像匹配,获取Y轴、X轴、Z轴线性误差,探讨误差与其分布规律、误差对放疗剂量分布影响。结果X轴是(-0.4±2.62)mm,Y轴是(1.41±5.26)mm,Z轴是(-0.82±2.32)mm;X轴、Y轴、Z轴摆位误差区间≤3 mm的发生率明显高于其他摆位误差区间(P<0.05);首次扫描、其他各次扫描的X轴、Y轴、Z轴之间对比,P<0.05;模拟未移床V5、V10、V20、V30、Dmax以及Dmean为原计划(102.42±5.33)%、(104.11±6.41)%、(106.40±13.42)%、(110.25±39.04)%、(98.22±6.720)%、(92.33±5.67)%、(88.13±9.39)%、(98.75±5.11)%;PTV D95与原计划对比,P<0.05。结论CBCT可纠正接受SBRT治疗NCSLC患者摆位误差,减少正常组织、靶区射线受量。

Management of oligometastatic non-small cell lung cancer patients:Current controversies and future directions

Oligometastatic non-small cell lung cancer(NSCLC)describes an intermediate stage of NSCLC between localized and widely-disseminated disease.This stage of NSCLC is characterized by a limited number of metastases and a more indolent tumor biology.Currently,the management of oligometastatic NSCLC involves radical treatment(radiotherapy or surgery)that targets the metastatic lesions and the primary tumor to achieve disease control.This approach offers the potential to achieve prolonged survival in patients who,in the past,would have only received palliative measures.The optimal therapeutic strategies for the different scenarios of oligometastatic disease(intracranial vs extracranial disease,synchronous vs metachronous)remain undefined.Given the lack of head-to-head studies comparing radiotherapy to surgery in these patients,the decision to apply surgery or radiotherapy(with or without systemic treatment)must be based on prognostic factors that allow us to classify patients.This classification will allow us to select the most appropriate therapeutic strategy on an individualized basis.In the future,the molecular or microRNA profiles will likely improve the treatment selection process.The objective of the present article is to review the most relevant scientific evidence on the management of patients with oligometastatic NSCLC,focusing on the role of radiotherapy and surgery.We also discuss areas of controversy and future directions.

Indications of external radiotherapy for hepatocellular carcinoma from updated clinical guidelines: Diverse global viewpoints

The etiology and disease patterns of hepatocellular carcinoma(HCC)significantly vary among regions. Modern standard treatments commonly require multidisciplinary approaches, including applications of up-to date medicine and advanced procedures, and necessitate the support of socioeconomic systems. For these reasons, a number of clinical guidelines for HCC from different associations and regions have been presented. External beam radiation therapy was contraindicated for HCC until a few decades ago, but with the development of new technologies, its application has rapidly increased as selective irradiation for tumorous lesions became possible. Most of the guidelines had been opposed or indifferent to radiotherapy in the past, but several guidelines have introduced indications and recommendations for radiotherapy in their updated versions. This review will discuss the characteristics of important guidelines and their contents regarding radiotherapy and will also provide guidance to physicians who are considering applications of locoregional modalities that include radiotherapy.

Technical Note: Identification of CT Texture Features Robust to Tumor Size Variations for Normal Lung Texture Analysis

Normal lung CT texture features have been used for the prediction of radiation-induced lung disease (RILD). For these features to be clinically useful, they should be robust to tumor size variations and not correlated with the normal lung volume of interest, i.e., the volume of the peri-tumoral region (PTR). CT images of 14 lung cancer patients were studied. Different sizes of gross tumor volumes (GTVs) were simulated and placed in the lung contralateral to the tumor. 27 texture features [nine from intensity histogram, eight from the gray-level co-occurrence matrix (GLCM) and ten from the gray-level run-length matrix (GLRM)] were extracted from the PTR. The Bland-Altman analysis was applied to measure the normalized range of agreement (nRoA) for each feature when GTV size varied. A feature was considered as robust when its nRoA was less than the threshold (100%). Sixteen texture features were identified as robust. None of the robust features was correlated with the volume of the PTR. No feature showed statistically significant differences (P 0.05) on GTV locations. We identified 16 robust normal lung CT texture features that can be further examined for the prediction of RILD.